1. Field of the Invention
The present invention relates to a method of dyeing a cellulose fiber textile product with a thermochromic material and/or a photochromic material and the product dyed by the method.
2. Description of the Prior Art
A three-component composition consisting of an acid developing substance, an acidic substance and a solvent has been well known as a kind of thermochromic material which shows reversible color changes as the temperature changes.
This composition is capable of producing commercial products having increased value in chromatic effect and function since it offers more diverse colors and higher coloring densities in comparison with thermochromic materials such as metal complex crystals and cholesteric liquid crystals and since dramatic changes occur between colored and colorless states. At present, the three-component composition described above is used in a microcapsular form except for only a very few uses, in order to keep its function unaffected by outside conditions since its excellent color changing function is obtained only in cases where its three components form a system at a strictly constant ratio.
With respect to photochromic materials, which show reversible color changes in the presence or absence of light, a wide variety of organic photochromic compounds have been developed which show more sensitive color changes between colored and colorless states, which offer more diverse colors and which are more compatible with various organic compounds such as synthetic resins in comparison with conventional inorganic photochromic compounds such as silver halides.
Such organic photochromic compounds are used as a solution or dispersion in an appropriate medium or in the form of microcapsules of a solution or dispersion in an appropriate medium.
None of these thermochromic materials and photochromic materials are capable of directly dyeing fiber because of a lack of affinity with fiber. Although dyeing is possible by the synthetic resin printing method, the synthetic resin padding method and other methods using an adhesive such as synthetic resin binder, the coloring density obtained with thermochromic material or photochromic material is extremely, i.e. markedly, lower than that obtained with an ordinary coloring agent. For example, in the case of the synthetic resin printing method, a fair coloring density is obtained only when bulky printing is conducted on a textile product using an ink containing such chromic material and synthetic resin binder at high concentrations. In this case, the surface of the textile product loses its fiber texture, its appearance worsens, and its color fastness to rubbing and color fastness to washing are insufficient. For these reasons, even when the entire surface of the cloth is colored, no commercially valuable product will be obtained. Therefore, it is the conventional practice to make patterns such as one-point patterns on a very narrow area on the cloth.
Also, when using the pigment resin padding method with high concentrations of thermochromic material and/or photochromic material and synthetic resin binder, these chromic materials are not capable of being thoroughly adsorbed because of a lack of substantivity with fiber, and physical adhesion as in the pigment resin printing method cannot be expected; therefore, nothing more than extremely low coloring density can be obtained. Moreover, the obtained fiber texture, appearance, color fastness to rubbing, and other properties are insufficient.